Acquisitions (Details) (USD $)	12 Months Ended
	Oct. 31, 2011 acquisitions	Oct. 31, 2010 acquisitions	Oct. 31, 2009 acquisitions
Acquisitions
Acquisitions:
Number of acquisitions	4	11	2
Number of large acquisitions		4
Purchase price allocation
In-process research and development	$ 3,000,000	$ 331,000,000	$ 7,000,000
Amortizable intangible assets	4,699,000,000	2,400,000,000	105,000,000
Net liabilities assumed	(206,000,000)
Net assets acquired	4,496,000,000
Goodwill	6,868,000,000	5,200,000,000	315,000,000
Total fair value of purchase consideration	11,364,000,000	9,400,000,000	390,000,000
Autonomy Corporation
Purchase price allocation
Amortizable intangible assets	4,600,000,000
Goodwill	6,600,000,000
Total fair value of purchase consideration	$ 11,000,000,000
Estimated weighted average life of the purchased intangibles (in years)	8.8
Equity interest acquired (as a percent)	99.00%
Equity interest expected to be acquired (as a percent)	100.00%